From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Daniel Axtens <dja@axtens.net>

Date: Fri, 8 Apr 2022 12:35:28 +1000

Subject: [PATCH] powerpc: do CAS in a more compatible way

I wrongly assumed that the most compatible way to perform CAS

negotiation was to only set the minimum number of vectors required

to ask for more memory. It turns out that this messes up booting

if the minimum VP capacity would be less than the default 10% in

vector 4.

Linux configures the minimum capacity to be 1%, so copy it for that

and for vector 3 which we now need to specify as well.

Signed-off-by: Daniel Axtens <dja@axtens.net>

(cherry picked from commit e6f02ad4e75cd995a8ee2954d28949c415b6cbfe)

---

 grub-core/kern/ieee1275/init.c | 54 ++++++++++++++++++++++++------------------

 1 file changed, 31 insertions(+), 23 deletions(-)

diff --git a/grub-core/kern/ieee1275/init.c b/grub-core/kern/ieee1275/init.c

index 9704715c83..ef55107467 100644

--- a/grub-core/kern/ieee1275/init.c

+++ b/grub-core/kern/ieee1275/init.c

@@ -298,33 +298,37 @@ grub_ieee1275_total_mem (grub_uint64_t *total)

 /* Based on linux - arch/powerpc/kernel/prom_init.c */

 struct option_vector2 {

-	grub_uint8_t byte1;

-	grub_uint16_t reserved;

-	grub_uint32_t real_base;

-	grub_uint32_t real_size;

-	grub_uint32_t virt_base;

-	grub_uint32_t virt_size;

-	grub_uint32_t load_base;

-	grub_uint32_t min_rma;

-	grub_uint32_t min_load;

-	grub_uint8_t min_rma_percent;

-	grub_uint8_t max_pft_size;

+  grub_uint8_t byte1;

+  grub_uint16_t reserved;

+  grub_uint32_t real_base;

+  grub_uint32_t real_size;

+  grub_uint32_t virt_base;

+  grub_uint32_t virt_size;

+  grub_uint32_t load_base;

+  grub_uint32_t min_rma;

+  grub_uint32_t min_load;

+  grub_uint8_t min_rma_percent;

+  grub_uint8_t max_pft_size;

 } __attribute__((packed));

 struct pvr_entry {

-	  grub_uint32_t mask;

-	  grub_uint32_t entry;

+  grub_uint32_t mask;

+  grub_uint32_t entry;

 };

 struct cas_vector {

-    struct {

-      struct pvr_entry terminal;

-    } pvr_list;

-    grub_uint8_t num_vecs;

-    grub_uint8_t vec1_size;

-    grub_uint8_t vec1;

-    grub_uint8_t vec2_size;

-    struct option_vector2 vec2;

+  struct {

+    struct pvr_entry terminal;

+  } pvr_list;

+  grub_uint8_t num_vecs;

+  grub_uint8_t vec1_size;

+  grub_uint8_t vec1;

+  grub_uint8_t vec2_size;

+  struct option_vector2 vec2;

+  grub_uint8_t vec3_size;

+  grub_uint16_t vec3;

+  grub_uint8_t vec4_size;

+  grub_uint16_t vec4;

 } __attribute__((packed));

 /* Call ibm,client-architecture-support to try to get more RMA.

@@ -345,13 +349,17 @@ grub_ieee1275_ibm_cas (void)

   } args;

   struct cas_vector vector = {

     .pvr_list = { { 0x00000000, 0xffffffff } }, /* any processor */

-    .num_vecs = 2 - 1,

+    .num_vecs = 4 - 1,

     .vec1_size = 0,

     .vec1 = 0x80, /* ignore */

     .vec2_size = 1 + sizeof(struct option_vector2) - 2,

     .vec2 = {

       0, 0, -1, -1, -1, -1, -1, 512, -1, 0, 48

     },

+    .vec3_size = 2 - 1,

+    .vec3 = 0x00e0, // ask for FP + VMX + DFP but don't halt if unsatisfied

+    .vec4_size = 2 - 1,

+    .vec4 = 0x0001, // set required minimum capacity % to the lowest value

   };

   INIT_IEEE1275_COMMON (&args.common, "call-method", 3, 2);

@@ -364,7 +372,7 @@ grub_ieee1275_ibm_cas (void)

   args.ihandle = root;

   args.cas_addr = (grub_ieee1275_cell_t)&vector;

-  grub_printf("Calling ibm,client-architecture-support...");

+  grub_printf("Calling ibm,client-architecture-support from grub...");

   IEEE1275_CALL_ENTRY_FN (&args);

   grub_printf("done\n");